Aeroplane



' June 27,1933. I B. s. WELSH-ER 1,915,809-

AEROPLANE Filed June 1, 1931 Patented June 27, 1933 1,915,809

UNITED STATES PATENT OFFICE BURDETTE STAR WELSHER, OF SAN LUIS OBISPO,CALIFORNIA AEROPLANE 1 Application filed June 1, 1931. Serial in.541,305.

In the drawing: same angle of attack at all times. The flaps Figure 1 isa drawing to show the method of the wing 2 will be independent of oneanused to connect the front part of the wing 1 other and will not beattached together and the flap 2. Hinges 3 allow 1 and 2 to, through thecontrols. 5 move dependent of one another. Numbers In Figure 2 thecenter of pressure is re- 9 are the vertical'sides of a fuselage. DDversed when the wing attempts to move as v and EE are section lines forFigure 2 and shown in Figure 3. This is because of the Figure 3. Noattempt has been made, in flap 2. I will use the action of the aileronon this figure, to show the mechanism at the end (he present dayaeroplane to illustrate this.

' 10 of the wing as shown in Figure 2. \Vhile flying in a ship of thepresent day type Figure 2 is a sectional view taken .on line if onewishes to bank he will cause the aileron DD of Fig. 1, drawn to a largerscal on one side of the ship to rise and the other howing the nechanismat the end of the on the other side t0 lOWGl'. 011 the side that wing.In addition to being a section line DD the aileron rises a lesser liftwill be apparent, may also designate the chord line of .the and on theside the aileron lowers a greater wing. Number 14 is a section of thevertical lift will be apparent. These unequal forces f l all h w as 9 iFi 1, N mform a couple and the ship Will be forced on ber 10 is a,bearing cap and seat for the its side. If the action 0f one oftheailerons wing supporting shaft 5 to t t in. on one side of this ship wasreversed te1n- N b 7 i th i f t ti a d i 1 porarily and both theailerons went up at the cated at the center of bearing 5. Numbers e e do n at e sa t as e 12 are the bearing cap bolts. Numbers 8 are flaps 2in th1s improvement do when 6' of fuselage section braces. Number 6 isthe g 1 2 8 moved it can be seen how the ratio point located as thecenter point of 8.1161011S prevlous coupling IEOI'CBS 02111 be b i i 13th t, lid i a h i t l transferred into forces tending to changedirection i id number 11, the center of pressure of the whole ship forNumber 41s a solid rod pivotaly attached at theforces are changed o igup a d 13 and 15. Number 16 is a solid rod attached o t about 7 of the ig h r A lidl t Q d i t ily t, 15; Th f m; study of the center ofpressure movement on t f th i 1 b means f h ft 5 i certain types ofairfoil will reveal that it 9 journaled in bearing 10 and the rear flap2 vanes Y a p l 9 h g is pivotally attached to 1 by 3. This figu chorddlstance. If the bearing 5 in Figure 2 ho h h th ti i t6 mQVes,the isplaced in the center of this movement a fl 2 l moves, very smallpressure at 70% of the wlng chord Fi 3 i a ti di a f Fi 2, from theleading edge will easily counteract 85 being a section on Figure 1 atEE. EE ma any rotat onal force caused by th1s original be considered asthe chord line of Figure 2 Center Of p su T 211186 of the change or DD,E1E1 dEQEQ are r d ti of the center of pressure when arrangements ofwhen the is in a, degree at- S hOWIl 111 Figure 2 are 1118i] 71th 15 due(511- t k b diti d a 10 degree angle f ttirely to the movement of theflap 2, and not tack condition. Are :20 is the line of motion of on thechange of angle of attack of the g- 3 drawn f m th t ti i t 7 A 4 i Themovement of the flap 2 overcomes the th li (if ti f 15 drawn f th atioriginal center of pressure of the wing. and point 6. In Figures 1, 2,and 3 thenumbers creates anol her that acts in the opposite di- 5 5designate the same parts. Figure 3 shows rection when correctly guided.how the flap 2 rotates on bearings 3' as the The wing has a regular wingcurve, namely front of the wing 1 rotates on the bearing 5 the N. A. C.A. M-12. Other wing curves if the ratio point 6 is held stationary. mayalso be used. The planform wing is di- The front parts of the wing 1extending on vided into two parts, 1 and 2, and are faseach side of thefuselage will each be at the tened together with hinges, numbers 3. The

wing bearings 5 are so placed on the wing chord DD that the wing will bebalanced at an angle of attack of +1.5 degrees with the relative wind,the center of pressure of the wing being directly over the point ofrotation of the wing 7. This position is about 25% of the wing chordfrom the leading edge. The flap 2 in this position will be unaltered asrespects the original wing in its original solid planform as shown inFigure 2.

The means of control over the wings angle of attack is the movement ofthe ratio point 6 in a horizontal direction of +or as shown in Figure 2.Moving 6 in a horizontal direction changes the angular movement of theflap 2 with respect to that of the wing 1. After the desirable angle ofattack has been found, in flight, and the ratio point 6 is sta tionary,the action that takes place on the wing 1 and the flap 2 is dependent onthe air forces and their directions. This secondary automatic action,caused by the change of direction of the air currents, goes on no matterat what angle of attack the wing is to the relative wind. Theexplanation of this action will be explained with the ratio point 6stationary, from Figure 3,1ater.

In Figure 2 the movements of the parts are as follows:

When the ratio point 6 moves forward point 15 moves forward, causing theflap 2 to move up. In flight this would cause the center of pressure tomove forward from over the point of rotation 7 and tend to turn the wing1 in a clockwise direction on bearings 5 until it had passed through acertain number of degrees where the center of pressure would again beover 7. When the ratio point 6 is moved backward point 15 moves a likenumber of degrees in the same direction, causing the flap 2 to move downa certain number of degrees. In flight this would cause the center ofpressure to move backward from over 7 and tend to turn the wing l in acounter clockwise direction on 5 until it had passed through a certainnumber of degrees where the wing would again be in equilibrium.

The wing will remain in the position shown in Figure 2 at all times whenflying in air that has no Vertical air currents if point 6 is held inthe position as shown. There will never be any force on the wing as I amgoing to use, but for explanation and descriptive matter suppose whilein flight one were to reach out of the cabin window and push down on theflap 2. Immediately the center of pressure of the wing would movebackward from point 5 and if the 'wing were released from the force justput on it' it would return to its original position of +1.5 degreesangle of attack with the relative wind. In a like manner if one were tolift up on the trailing edge of theflap 2 the center of pressure wouldgo forward and if the wing were again released it would go back to theformer +1.5 degree angle of attack position.

From Figure 3 it can be seen how the flap 2 changes its angle of attackdependent on the wing 1 as the wings angle of attack changes by drawingarcs a; and g from their respective rotation points, 7 and (S. The arca; is constant and cannot be changed. The arc y may be changed by movingpoint 6 in a vertical direction. This movement vertically need not bemade after the ideal distance from the rotation point 7 to the ratiopoint 6 has been found. There is a certain positional distance from thecenter of rotation 7 of the wing l to the ratiopoint 6 that'will givethe ideal angular rotation for the flap 2 to have in relation to theangular rotation of the wing 1. In the particular case of the wing andflap in Figure 2, the length of the rod 16 or distance 3-15 to thedistance 76 is in a ratio of 7: 10. l/Vith this ideal leverage the wingcan change its angle with the ground from 0 degrees to14 degrees and thelift will remain the same providing the angular change is caused by therelative wind and the ratio point is held. Suppose while flying alongone were to hit a. vertical air current going upward and the flap 2 hada leverage of less than .7, the bump would be more than counteracted andthe ship would drop. If the leverage of the flap were more than .7 thewing would not counteract the bump and the ship would rise with thebump. The wings would act inversly to a vertical air current going inthe opposite direction.

In a previous paragraph I illustrated how the flap 2 when moved up ordown would rotate the wing 1 bychanging itscenter of pressure. Now ifthe flap is held stationary by holding 6 and only allowed to move as thefront part of the wing 1 rotates, just as the center of pressure changedwhen 2 was moved so when the directional change of relative wind causesthe flaps to move the wing 1 will move-also. Therefore whenever there isa change of relative wind the wing changes its position and form withthe lift remaining constant. In Figure 3 ElEl will be the first positionof the wing with the relative wind parallel to E1151. If the relativewind changes to E2E2 the wing will change to ing edge flap hingedlymounted thereon, bearings in said fuselage, a shaft rigidlyinterconnecting said forward parts near the leading edge thereof andjournaled .in said bearings, a pair of levers each having one endconnected to the upper forward portion of a flap, the other end slidablyconnected to said fuselage forward of and below said flap for horizontalmovement and means for moving each lever whereby displacement of saidwing about its axis of rotation changes the angle of the flap to thewing to create a force tending to restore the wing to its originalposition.

2. In an aeroplane, an entire lifting surto extend equally in distanceand area on each side away from the longitudinal plane of symmetry ofthe body, and a flap consisting of the remainder of the area hingedlyconnected to the first part, means pivotally connected to the. upperforward portion of the flap adapted to be extended downwardly andforwardly for sliding attachment below said flap to said fuselage.

BURDETTE STAR WELSHER.

